Results from our past research confirmed out basic concept, that the sympathetic nervous system (SNS) aside from its well known short-term vasomotor effect, may also have a long-term trophic effect on the arterial wall. Specifically, the aorta and iliac arteries from long-term chemically sympathectomized rabbits evidenced functional and metabolic changes which resembled changes due to aging. We are now proposing a multidisciplinary study in which the trophic influence of SNS will be analyzed: 1) In view of different susceptibility to degenerative diseases, arteries from selected regions will be studied. 2) Whether the trophic influence of the SNS can be attributed to a specific component of the adrenergic system will be analyzed by modulation of the SNS in the arterial wall: a) to achieve normalization of norepinephrine level following nerve endings degenerations or, b) to maintain nerve endings intact with concomittant significant transmitter depletion. 3) Furthermore, it will be determined whether the trophic changes in the arterial wall are reversible after regeneration os the sympathetic innervation. 4) The possible trophic effect of SNS on the endothelial lining will be studied in denudation experiments. Multidisciplinary analysis of all variables will be based on a combination of physiologic and biochemical methods on one side and morphology with special emphasis on quantitative morphometry on the other. Our goal is to improve the understanding regarding the trophic influence on the SNS on the arterial wall, its relationship to vascular degenerative diseases and ultimately, to extrapolate this knowledge to more effective therapy and possibly prevention.